Current active RFID/passive RFID systems are turned on 24 hours which may cause Electromagnetic interference to medical devices used in hospital. Furthermore, the electromagnetic fields generated by RFID readers have been measured in laboratory conditions, as recounted in a report by AFSSET, the French agency for safety in the environment and at work, renamed Anses in 2010. The field emitted in the LF and HF bands quickly fades and is only significant in the immediate vicinity of a reader. In any case, this radiation remains lower than the threshold limit value for humans recommended by the ICNIRP, the International Commission on Non-Ionizing Radiation Protection (maximum permitted magnetic field=400 nT for HF technology and 105 nT for UHF). Although, in UHF frequency bands, the magnetic fields span greater distances, measurements have shown that the radiation does not exceed the threshold limit values.
Another test performed by department of electrical engineering at University of Texas at Arlington, Tex., USA concluded that if the RFID reader antennas at distances of 10 cm from the human head operating additively, it will contribute to a SAR in the human head of up to a maximum of 2.02763 W/kg, which is above the limit for safe exposure of RF radiation as allowed by FCC in US. The prolong exposure to this RF radiation may cause side effect to human body.